TPS1HB50-Q1: TPS1HB50-Q1 - Not proper power on

Selvakumar Sonai

Part Number: TPS1HB50-Q1

Hi Team,

Please find the schematic, we have seen some glitches at every power on its output.

Scope image :

Please review the schematic and scope images. Let us know what are the reason may cause this problem, Let me know how do fix this.

Thanks,

Selva

over 3 years ago

0 Yichi Zhang. over 3 years ago

TI__Genius 16390 points

Hi Selva,

Could you probe the SNS pin voltage as well as the current so we can get more information? Also what's the load profile?

Regards,

Yichi

0 Selvakumar Sonai over 3 years ago in reply to Yichi Zhang.

Prodigy 80 points

Hi Yichi,

Please find the change in the circuit, I changed the ISNS resistor value to 406 ohms.

I removed the ILIMIT resistor, now it is in the open state.

and capture waveform at initial power on.

Waveform

By calculation it is loading 7A during the power up condition.

Thanks,

selva

0 Selvakumar Sonai over 3 years ago in reply to Selvakumar Sonai

Prodigy 80 points

Hi Yichi,

Please find the Waveform

Channel 1 - Output 12V

Channel 2 - ISNS - Current sense from pin 2 of TPS1HB50A-Q1

Channel 3 - Current Probe at Input 12V.

Current probe 100mV/A - So 1V peak is measured during power on. 1V/100mV = 10A.

Thanks,

Selva

0 Yichi Zhang. over 3 years ago in reply to Selvakumar Sonai

TI__Genius 16390 points

Hi Selva,

This is likely due to current hits the current limit and shut off immediately. The SNS voltage is reading I(SNSFH)*R indicates there's a fault. Although the current reading is 10A compared to the internal threshold 14A, could you use a current probe and zoom in to see if it hits around 14A?

Is this behavior okay during start up? If not, maybe version B with higher current limit is more suitable in this application.

Please let me know if you have additional questions.

Regards,

Yichi

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TPS1HB50-Q1: TPS1HB50-Q1 - Not proper power on